Strengthening Relations in Military Communities Act of 2021 This bill requires the Office of Diversity Management and Equal Opportunity within the Department of Defense (DOD) to survey members of the Armed Forces and their family members who live in covered communities regarding relations between such individuals and their communities. Under the bill, covered community means a military installation and the area within 10 miles of the installation. DOD must report on the survey results every other year. The bill requires DOD to designate 10 geographically diverse military installations for review in each survey and make the results of the survey reports publicly available on a DOD website.